<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        
    </style>
</head>
<body>
    <div class="app">
        你好，我是 {{ name }}，今年 {{ age }} 岁
    </div>
</body>
<script src="https://unpkg.com/vue@3/dist/vue.global.js"></script>
<script>
    const {createApp}  = Vue;
    const app = createApp({
        data(){
            return {
                name:"张三",
                age:18
            }
        }
    }).mount(".app");
    console.log(app)
</script>
</html>